The present invention relates to a knife to be mounted in an oscillating tool for cutting through the adhesive that fastens a window pane in place, especially in a motor vehicle. The window panes, especially the windshields, of contemporary motor vehicles are fastened to the body with adhesive in order to improve resistance to wind, etc. When the panes are damaged and need to be replaced it becomes necessary to cut through the layer of adhesive, which is sometimes very thick and tough. This be done by hand unsatisfactorily or not at all. Oscillating tools that allow the layer to be cut through in one rapid operation have accordingly been developed and eliminate any problems in replacing the panes, at least with respect to cutting. It has, nevertheless, turned out that the oscillating knife cannot be guided along the layer of adhesive and tends to slip out laterally, resulting in damage to the window frame or other areas of the body. A malfunction of this type can of course also damage the edge of the knife if it encounters metal.